U.S. patent number 7,348,969 [Application Number 10/748,880] was granted by the patent office on 2008-03-25 for passive light stylus and user input device using same.
This patent grant is currently assigned to 3M Innovative Properties Company. Invention is credited to Bernard O. Geaghan, Michael J. Robrecht.
United States Patent |
7,348,969 |
Robrecht , et al. |
March 25, 2008 |
Passive light stylus and user input device using same
Abstract
The present disclosure provides a passive light stylus that
produces a defined intensity profile detectable by a user input
device when at least a portion of a tip of the stylus is proximate
an input surface of the user input device. In some embodiments, the
stylus includes a housing including an entrance aperture configured
to collect ambient light and an exit aperture configured to emit
the collected light, where the exit aperture is proximate a tip of
the stylus. The stylus also includes a light guide disposed within
the housing, where the light guide is in optical communication with
the entrance aperture and the exit aperture such that the light
guide directs collected light from the entrance aperture to the
exit aperture.
Inventors: |
Robrecht; Michael J.
(Shorewood, WI), Geaghan; Bernard O. (Salem, NH) |
Assignee: |
3M Innovative Properties
Company (St. Paul, MN)
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Family
ID: |
34710995 |
Appl.
No.: |
10/748,880 |
Filed: |
December 30, 2003 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20050146517 A1 |
Jul 7, 2005 |
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Current U.S.
Class: |
345/179;
178/19.05 |
Current CPC
Class: |
G06F
3/03542 (20130101); G06F 3/03545 (20130101); G06F
3/042 (20130101) |
Current International
Class: |
G06F
3/033 (20060101) |
Field of
Search: |
;345/179-183
;178/19.01,19.05 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
0 595 482 |
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May 1994 |
|
EP |
|
58-086674 |
|
May 1983 |
|
JP |
|
60-198630 |
|
Oct 1985 |
|
JP |
|
60-200388 |
|
Oct 1985 |
|
JP |
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61-006729 |
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Jan 1986 |
|
JP |
|
61-075423 |
|
Apr 1986 |
|
JP |
|
10-187348 |
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Jul 1998 |
|
JP |
|
10-283113 |
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Oct 1998 |
|
JP |
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11-282628 |
|
Oct 1999 |
|
JP |
|
2003-66417 |
|
Mar 2003 |
|
JP |
|
WO 03/058588 |
|
Jul 2003 |
|
WO |
|
WO 03/071345 |
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Aug 2003 |
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WO |
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Other References
US. Appl. No. 10/721,603, filed Nov. 25, 2003, entitled
"Light-Emitting Stylus and User Input Device Using Same". cited by
other .
U.S. Appl. No. 10/721,685, filed Nov. 25, 2003, entitled "Light
Emitting Stylus and User Input Device Using Same". cited by
other.
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Primary Examiner: Osorio; Ricardo
Claims
What is claimed is:
1. A stylus for use with a user input device, comprising: a housing
comprising an entrance aperture configured to collect ambient light
and an exit aperture configured to emit the collected light,
wherein the exit aperture is proximate a tip of the stylus; and a
light guide disposed within the housing, wherein the light guide is
in optical communication with the entrance aperture and the exit
aperture such that the light guide directs collected light from the
entrance aperture to the exit aperture; wherein the stylus produces
a defined intensity profile detectable by the user input device
when at least a portion of the tip of the stylus is proximate an
input surface of the user input device.
2. The stylus of claim 1, wherein the entrance aperture is
proximate an end of the housing opposite the tip.
3. The stylus of claim 1, wherein the entrance aperture is
proximate the tip.
4. The stylus of claim 3, wherein the entrance aperture is
configured to collect ambient light including light emitted by the
user input device.
5. The stylus of claim 1, wherein the entrance aperture comprises a
collector to collect ambient light.
6. The stylus of claim 5, wherein the collector comprises a
lens.
7. The stylus of claim 1, wherein the light guide is an integral
part of the housing.
8. The stylus of claim 7, wherein the light guide comprises a
reflective inner surface of the housing.
9. The stylus of claim 1, wherein the light guide comprises a
multilayer polymeric optical film.
10. The stylus of claim 9, wherein the multilayer polymeric optical
film reflects at least 80% of light incident thereon.
11. The stylus of claim 10, wherein the multilayer polymeric
optical film reflects at least 95% of light incident thereon.
12. The stylus of claim 11, wherein the multilayer polymeric
optical film reflects at least 99% of light incident thereon.
13. The stylus of claim 1, wherein the stylus comprises an optical
element proximate the tip of the stylus in optical communication
with the light guide, wherein the optical element focuses the
emitted light to a point.
14. The stylus of claim 1, wherein the tip of the stylus comprises
a conformable member that is configured to contact the input
surface of the user input device.
15. The stylus of claim 14, wherein the conformable member is an
integral part of the housing.
16. The stylus of claim 14, wherein a portion of the conformable
member is located within the housing and another portion extends
beyond the housing to form the exit aperture.
17. The stylus of claim 14, wherein the conformable member
comprises a sleeve that fits over the housing proximate the tip and
extends beyond the housing to form the exit aperture.
18. The stylus of claim 14, wherein the conformable member
comprises a polymeric material.
19. The stylus of claim 14, wherein the conformable member
comprises rubber.
20. The stylus of claim 1, wherein the stylus further comprises a
resilient member coupled to a cylinder positioned within the
housing proximate the tip, wherein the cylinder forms the exit
aperture, wherein the cylinder is slidably coupled to the tip such
that the cylinder changes the cross-sectional area of the emitted
light when at least a portion of the tip is in contact with the
input surface of the user input device.
21. The stylus of claim 1, wherein the defined intensity profile
comprises a dark region at least partially surrounding a light
region, wherein the contrast between the dark region and the light
region is detectable by the user input device.
22. A user input device, comprising: a plurality of light sensors
disposed to detect light transmitted through an input surface of
the user input device; a stylus configured to collect ambient light
and emit the collected light through a tip of the stylus, wherein
the stylus produces a defined intensity profile detectable by the
user input device when at least a portion of the tip of the stylus
is proximate the input surface of the user input device; and
electronics coupled to the plurality of light sensors and
configured to determine the location of the defined intensity
profile produced by the stylus at a reference plane.
23. The device of claim 22, wherein the stylus further comprises: a
housing comprising an entrance aperture configured to collect
ambient light and an exit aperture configured to emit the collected
light, wherein the exit aperture is proximate the tip of the
stylus; and a light guide disposed within the housing, wherein the
light guide is in optical communication with the entrance aperture
and the exit aperture such that the light guide directs the
collected light from the entrance aperture to the exit
aperture.
24. The device of claim 22, wherein the input surface comprises an
exterior surface of an electronic display.
25. The device of claim 24, wherein the electronic display
comprises a liquid crystal display.
26. The device of claim 24, wherein the electronic display
comprises an organic electroluminescent display.
27. The device of claim 24, wherein the plurality of light sensors
are integrated into a transistor array that controls pixels of the
electronic display.
28. The device of claim 22, wherein the reference plane is the
input surface.
29. An electronic display system, comprising: a user input device,
wherein the user input device comprises: a plurality of light
sensors disposed to detect light transmitted through an input
surface of the user input device; a stylus configured to collect
ambient light and emit the collected light through a tip of the
stylus, wherein the stylus produces a defined intensity profile
detectable by the plurality of light sensors of the user input
device when at least a portion of the tip of the stylus is
proximate the input surface of the user input device; and
electronics coupled to the plurality of light sensors and
configured to determine the location of the defined intensity
profile produced by the stylus at a reference plane; and an
electronic display disposed to display information through the
input surface of the user input device.
30. The system of claim 29, wherein the electronic display is a
liquid crystal display.
31. The system of claim 30, wherein the plurality of light sensors
is incorporated into the liquid crystal display.
32. The system of claim 29, wherein the electronic display
comprises a plurality of organic electroluminescent light-emitting
devices.
33. The system of claim 32, wherein at least a portion of the
plurality of organic electroluminescent light-emitting devices are
used as the plurality of light sensors.
34. A method for using an input device, comprising: providing a
stylus configured to collect ambient light and emit the collected
light through a tip, wherein the stylus produces a defined
intensity profile; providing an input device comprising a plurality
of light sensors disposed to detect the defined intensity profile
produced by the stylus when the defined intensity profile is
transmitted through an input surface of the input device;
positioning the stylus proximate the input surface of the input
device; detecting the defined intensity profile only when at least
a portion of the tip of the stylus is proximate the input surface
of the input device; and determining the location of the defined
intensity profile at a reference plane.
Description
This disclosure relates to a passive light stylus and the use of a
passive light stylus in a user input device.
BACKGROUND
Touch sensors have become an increasingly common way for users to
intuitively interact with electronic systems, typically those that
include displays for viewing information. In many applications, the
information is viewed through the touch-sensitive area so that the
user seems to interact directly with the displayed information.
Depending on the technology of the input device, a user may
interact with the device using a finger or some other touch
implement such as a stylus. When a stylus is used, it can be a
passive object (as is typical for those used with resistive touch
screens, for example, in a personal digital assistant or other
hand-held device) or an active object (as is typical for those used
with signature capture devices). A passive stylus can include a
simple pen-shaped object that contacts a touch screen.
SUMMARY
The present disclosure provides a passive light stylus for use with
a user input device.
In one aspect, the present disclosure provides a stylus for use
with a user input device that includes a housing including an
entrance aperture configured to collect ambient light and an exit
aperture configured to emit the collected light, where the exit
aperture is proximate a tip of the stylus. The stylus further
includes a light guide disposed within the housing, where the light
guide is in optical communication with the entrance aperture and
the exit aperture such that the light guide directs collected light
from the entrance aperture to the exit aperture. The stylus
produces a defined intensity profile detectable by the user input
device when at least a portion of the tip of the stylus is
proximate an input surface of the user input device.
In another aspect, the present disclosure provides a user input
device that includes a plurality of light sensors disposed to
detect light transmitted through an input surface of the user input
device. The user input device also includes a stylus configured to
collect ambient light and emit the collected light through a tip of
the stylus, where the stylus produces a defined intensity profile
detectable by the user input device when at least a portion of the
tip of the stylus is proximate the input surface of the user input
device. The user input device further includes electronics coupled
to the plurality of light sensors and configured to determine the
location of the defined intensity profile produced by the stylus at
a reference plane.
In another aspect, the present disclosure provides an electronic
display system that includes a user input device. The user input
device includes a plurality of light sensors disposed to detect
light transmitted through an input surface of the user input
device. The user input device also includes a stylus configured to
collect ambient light and emit the collected light through a tip of
the stylus, where the stylus produces a defined intensity profile
detectable by the plurality of light sensors of the user input
device when at least a portion of the tip of the stylus is
proximate the input surface of the user input device. The user
input device also includes electronics coupled to the plurality of
light sensors and configured to determine the location of the
defined intensity profile produced by the stylus at a reference
plane. The electronic display system also includes an electronic
display disposed to display information through the input surface
of the user input device.
In another aspect, the present disclosure provides a method for
using an input device that includes providing a stylus configured
to collect ambient light and emit the collected light through a
tip, where the stylus produces a defined intensity profile. The
method further includes providing an input device including a
plurality of light sensors disposed to detect the defined intensity
profile produced by the stylus when the defined intensity profile
is transmitted through an input surface of the input device. The
method further includes positioning the stylus proximate the input
surface of the input device, detecting the defined intensity
profile only when at least a portion of the tip of the stylus is
proximate the input surface of the input device, and determining
the location of the defined intensity profile at a reference
plane.
The above Summary of the present disclosure is not intended to
describe each disclosed embodiment or every implementation of the
present disclosure. The Figures and the Detailed Description that
follow more particularly exemplify these embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional diagram of an embodiment of a
stylus.
FIG. 2(a) is a schematic cross-sectional diagram of an embodiment
of a portion of a stylus that includes a conformable member
proximate a tip of the stylus.
FIG. 2(b) is a schematic cross-sectional diagram of another
embodiment of a portion of a stylus that includes a conformable
member proximate a tip of the stylus.
FIG. 3 is a schematic cross-sectional diagram of an embodiment of a
portion of a stylus that includes an optical element proximate a
tip of the stylus.
FIG. 4(a) is a schematic cross-sectional diagram of an embodiment
of a portion of a stylus that includes a resilient member coupled
to a cylinder positioned within a housing of the stylus proximate a
tip of the stylus.
FIG. 4(b) is a schematic cross-sectional diagram of the portion of
the stylus of FIG. 4(a) with at least a portion of the tip of the
stylus contacting an input surface of a user input device.
FIG. 5 is a schematic cross-sectional diagram of an embodiment of a
portion of a stylus that includes an entrance aperture proximate a
tip of the stylus.
FIG. 6 is a schematic cross-sectional diagram of another embodiment
of a portion of a stylus that includes an entrance aperture
proximate a tip of the stylus and a resilient member coupled to a
cylinder positioned within a housing of the stylus proximate the
tip of the stylus.
FIGS. 7(a)-(c) are schematic diagrams of various embodiments of
defined intensity profiles that may be produced by a stylus of the
present disclosure.
FIGS. 8(a)-(b) are schematic diagrams of an embodiment of one way
of using a passive light stylus in a user input device.
DETAILED DESCRIPTION
The present disclosure relates to a passive light stylus and its
use with a light sensitive user input device (hereinafter referred
to as a "user input device"). In some embodiments, the present
disclosure provides a stylus that collects ambient light and
directs the collected light toward an input surface of the user
input device. Using the collected light, the stylus produces a
defined intensity profile that is detectable by the user input
device when at least a portion of a tip of the stylus is proximate
an input surface of the user input device.
The styli of the present disclosure can be used and detected in
much the same way that an active light-emitting stylus is used. In
contrast to an active light-emitting stylus, a passive stylus does
not require a power supply. In addition, a passive stylus may also
have the advantage of not being detectable unless a tip of the
stylus is very near or in contact with an input surface of a user
input device. Some active styli require a switching mechanism to
control detection. Such mechanisms can fail over time due to use.
Passive styli, on the other hand, do not require such switching
mechanisms.
FIG. 1 is a schematic cross-sectional diagram of an embodiment of a
stylus 10. The stylus 10 includes a housing 12 and a light guide 20
disposed within the housing 12. The housing 12 includes an entrance
aperture 14 and an exit aperture 16 proximate a tip 18 of the
stylus 10. In the embodiment illustrated in FIG. 1, the entrance
aperture 14 is located proximate an end of the housing 12 opposite
the tip 18. Any suitable material or materials may be used to form
housing 12. Further, housing 12 can take any suitable form. It may
be preferred that the housing 12 is configured such that it is
capable of being easily held and maneuvered by a human hand.
Proximate the end of the housing 12 opposite the tip 18 is the
entrance aperture 14. In the embodiment shown in FIG. 1, the
entrance aperture 14 is configured to collect ambient light. As
used herein, the term "ambient light" refers to light that is
present in the environment around a detecting or interpreting
device, such as a user input device, and generated from outside
sources. Ambient light can include light produced by a user input
device. In some embodiments, the entrance aperture 14 may be
positioned proximate the tip 18 of stylus 10 as is further
described herein, or it may be located at any suitable position
along housing 12. The entrance aperture 14 may take any suitable
shape for collecting ambient light, e.g., circular, rectangular,
polygonal, cylindrical. In some embodiments, the entrance aperture
14 may include a portion that recesses into the housing in any
suitable shape, e.g., frustoconical. The entrance aperture 14 can
include one or more apertures configured to collect light. Further,
entrance aperture 14 may include any suitable surface, e.g.,
reflective, absorptive, textured. It may be preferred that the
surface of entrance aperture 14 includes a multilayer polymeric
optical film such as those described, e.g., in U.S. Pat. No.
6,080,467 to Weber et al., entitled HIGH EFFICIENCY OPTICAL
DEVICES.
An optional collector 15 may be positioned proximate entrance
aperture 14 to assist in collecting ambient light. Any suitable
collector 15 may be used, e.g., lens or lenses, domed lenses,
etc.
Proximate the tip 18 of housing 12 is the exit aperture 16. The
exit aperture 16 is configured to emit light collected by the
entrance aperture 14. In other words, the exit aperture 16 pipes or
directs light collected by the entrance aperture 14 away from the
tip 18 of stylus 10. The exit aperture 16 may take any suitable
shape for emitting light, e.g., circular, rectangular, polygonal,
etc. The exit aperture 16 may include any suitable surface that is
conducive to emitting light, e.g., a transparent surface or a
reflective surface. It may be preferred that the surface of the
exit aperture 16 include a multilayer polymeric optical film such
as those described, e.g., in U.S. Pat. No. 6,080,467.
Disposed within the housing 12 of stylus 10 is the light guide 20.
As shown in FIG. 1, the light guide 20 is in optical communication
with the entrance aperture 14 and the exit aperture 16 such that
the light guide 20 directs collected light from the entrance
aperture 14 to the exit aperture 16. The light guide 20 can include
any suitable material or materials, e.g., glass, polymeric. In some
embodiments, the light guide 20 can include one or more optical
fibers, e.g., polymer-clad silica fibers. In some embodiments, the
light guide 20 may include an inner space that is filled with air
or other medium for directing light. Further, in some embodiments,
the light guide may be an integral part of the housing 12. In other
words, the housing 12 may include an inner space that is filled
with air or other medium for directing light. In other embodiments,
the light guide 20 can be a reflective inner surface of the housing
12. Any suitable reflective inner surface may be included, e.g.,
metal, polymeric, painted, etc. It may be preferred that the
reflective inner surface of the housing include a multilayer
polymeric optical film such as those described, e.g., in U.S. Pat.
No. 6,080,467. It may be preferred that the reflective inner
surface reflects at least 80% of light incident thereon. It may be
more preferred that the reflective inner surface reflects at least
95% of light incident thereon. It may be even more preferred that
the reflective inner surface reflects at least 99% of light
incident thereon.
In operation, the stylus 10 produces a defined intensity profile
detectable by a user input device when at least a portion of the
tip 18 of the stylus 10 is proximate an input surface of the user
input device as is further described herein. When at least a
portion of the tip 18 of stylus 10 is proximate the input surface
of the user input device, the tip 18 can either be in contact with
the input surface or at least within a distance from the input
surface that is sufficiently small so that the detectable intensity
profile is maintained at least at the level of the input surface.
Further, as used herein, the term "defined intensity profile"
refers to a predictable light pattern produced by a stylus of the
present disclosure, the light pattern having one or more dark
regions that at least partially surround one or more light regions,
where the contrast between the one or more dark regions and the one
or more light regions is sufficient for detection by a user input
device. What constitutes sufficiency for detection can be adjusted
by setting detection thresholds, with the caveat that lower
thresholds may result in a device that is more susceptible to
noise.
FIGS. 2(a)-(b) schematically illustrate some non-limiting
embodiments of styli according to the present disclosure. FIG. 2(a)
is a schematic cross-sectional diagram of an embodiment of a
portion of a stylus 110 that includes a housing 112 and a light
guide 120 disposed within the housing 112. Stylus 110 also includes
an entrance aperture (not shown) for collecting ambient light, and
an exit aperture 116 proximate a tip 118 of the stylus 110 for
emitting light. All of the design considerations and possibilities
described herein with respect to the housing 12, the light guide
20, the entrance aperture 14, and the exit aperture 16 of the
embodiment illustrated in FIG. 1 apply equally to the housing 112,
the light guide 120, the entrance aperture (not shown), and the
exit aperture 116 of the embodiment illustrated in FIGS.
2(a)-(b).
The stylus 110 also includes a conformable member 130 proximate the
tip 118 of the stylus 110. The conformable member 130 can be made
of any suitable material or materials, e.g., polymeric, rubber,
silicone. The conformable member 130 is configured to contact an
input surface of a user input device. The conformable member 130
may allow the stylus 110 to contact the input surface of the user
input device such that a defined intensity profile is produced by
the stylus 110. Further, the conformable member 130 may also allow
a user to more easily contact the input surface with the stylus 110
without damage to the input surface. In addition, the conformable
member 130 may allow the user to more easily drag the tip 118 of
the stylus across the input surface while scrolling through menus
or writing text.
In some embodiments, the conformable member 130 is integral with
the housing 112 of stylus 110. Alternatively, in some embodiments,
the conformable member 130 may be a separate member that is
connected to the tip 118 of stylus 110 in any suitable manner. For
example, as illustrated in FIG. 2(a), the conformable member 130
includes a sleeve that fits over the housing 112 proximate the tip
118 and extends beyond the housing 112 to form the exit aperture
116.
FIG. 2(b) is a schematic cross-sectional diagram of another
embodiment of a portion of a stylus 110 that includes a conformable
member 130 having a portion that is located within the housing 112
of stylus 110 and another portion that extends beyond the housing
112 to form an exit aperture 116.
The passive light styli of the present disclosure can also include
one or more optical elements in optical communication with a light
guide to produce a defined intensity profile. For example, FIG. 3
is a schematic cross-sectional diagram of an embodiment of a
portion of a stylus 210 that includes a housing 212 and a light
guide 220 disposed within the housing 212. The stylus 210 can
include any suitable stylus described herein, e.g., stylus 10 of
FIG. 1. The stylus 210 also includes an optical element 240
proximate a tip 218 of the stylus 210. The optical element 240 can
include any suitable optical element or elements, e.g., lenses,
etc. The optical element 240 can be positioned proximate the tip
218 of the stylus 210 such that it is in optical communication with
the light guide 220. As shown in FIG. 3, the optical element 240 is
positioned proximate the tip 218 using supports 242. Although the
optical element 240 is shown as being positioned outside of housing
212, in some embodiments, the optical element 240 may be positioned
within the housing 212.
In general, light is collected by an entrance aperture (e.g.,
entrance aperture 14 of FIG. 1) and directed by the light guide 220
through the optical element 240. The optical element 240 in turn
focuses the emitted light to a point P, thereby producing a defined
intensity profile that is detectable by a user input device as is
further described herein.
As is also described herein, the passive light styli of the present
disclosure produce defined intensity profiles that are detectable
by a user input device. In some embodiments, a stylus may be
configured such that a light beam emitted by the stylus may have a
property that abruptly changes when at least a portion of a tip of
the stylus sufficiently contacts an input surface of a user input
device as is further described in co-assigned and co-pending U.S.
patent application Ser. No. 10/721,603, filed Nov. 25, 2003.
For example, FIGS. 4(a)-(b) schematically illustrate some
non-limiting examples of mechanisms for abruptly changing a
property of a light beam emitted by a stylus according to the
present disclosure. FIGS. 4(a)-(b) illustrate a portion of a
passive light stylus 310 that includes a housing 312 and a light
guide 320 disposed within the housing 312. FIG. 4(a) indicates a
tip position when the stylus 310 is not in contact with a surface,
and FIG. 4(b) indicates a tip position when the stylus 310 is
contacting a surface. Stylus 310 may include any suitable stylus
described herein, e.g., stylus 10 of FIG. 1.
Also positioned within the housing 312 is a resilient member 350
coupled to a cylinder 352. The cylinder 352 forms an exit aperture
316. The cylinder 352 is slidably coupled to a tip 318 of housing
312 such that the cylinder 352 changes the cross-sectional area of
the emitted light beam when at least a portion of the cylinder 352
is in contact with an input surface of a user input device. As
shown, when the cylinder 352 is not in contact with a surface (FIG.
4(a)), the exit aperture 316 is farther away from the end of the
light guide 320, resulting in a narrower beam spread B. When the
tip 318 is in contact with a surface (FIG. 4(b)), the exit aperture
316 is closer to the end of the light guide 320, resulting in a
broader beam spread B'.
Various other embodiments of styli according to the present
disclosure may include alternative positioning of either or both of
the entrance aperture and the exit aperture. For example, FIG. 5 is
a schematic cross-sectional diagram of an embodiment of a portion
of a stylus 410 that includes a housing 412 and a light guide 420
disposed within the housing 412. All of the design considerations
and possibilities described herein with respect to the housing 12
and the light guide 20 of the embodiment illustrated in FIG. 1
apply equally to the housing 312 and the light guide 320 of the
embodiment illustrated in FIG. 5. One difference between the stylus
10 of FIG. 1 and the stylus 410 of FIG. 5 is that the stylus 410
includes an entrance aperture 414 proximate a tip 418 of the stylus
410. Another difference is that the stylus 410 also includes a
reflector 460 disposed within the housing 412. Any suitable
reflector may be used, e.g., metal, polymeric, etc. The reflector
460 may also include any suitable shape, e.g., parabolic,
elliptical, etc.
In general, the entrance aperture 414 collects ambient light,
including light that may be emitted by an input device proximate
the tip 416. The collected ambient light is represented as beam I
in FIG. 5. The collected light I is directed by the light guide 420
to the reflector 460. Reflector 460 then directs the light R back
through the light guide 420 where it is emitted by an exit aperture
416 proximate the tip 418 of stylus 410. The stylus 410 produces a
defined intensity profile that is detectable by a user input device
when at least a portion of the tip 418 of the stylus 410 is
proximate (i.e., sufficiently close to or in contact with) an input
surface of the device. If the tip 418 of the stylus 410 is in
contact with the input surface, most of the light collected by the
entrance aperture 414 will be light emitted by the user input
device.
Alternatively, the present disclosure also includes a stylus that
collects and emits light proximate a tip of the stylus and also
includes a mechanism for abruptly changing a property of the
emitted light. For example, FIG. 6 is a schematic cross-sectional
diagram of another embodiment of a portion of a stylus 510 that
includes an entrance aperture 514 proximate a tip 518 of the stylus
510. Stylus 510 is similar in many respects to stylus 410 of FIG.
5. For example, the stylus 510 includes a housing 512 and a first
light guide 520 disposed within the housing 512. The stylus 510
also includes a reflector 560 disposed within the housing 512 to
reflect light collected by the entrance aperture 514. One
difference between the stylus 410 of FIG. 5 and that of stylus 510
of FIG. 6 is that stylus 510 also includes a resilient member 550
coupled to a cylinder 552 positioned within the housing 512 of the
stylus 510 proximate the tip 518 of the stylus 510. The stylus 510
also includes a second light guide 522 that is in optical
communication with the first light guide 520 such that light
reflected by reflector 560 is directed through the first light
guide 520 and into the second light guide 522.
The cylinder 552 forms the exit aperture 516 of the stylus 510. The
cylinder 552 is slidably coupled to the tip 518 such that the
cylinder 552 changes the cross-sectional area of the emitted light
when at least a portion of the cylinder 552 is in contact with the
input surface of a user input device. As described herein with
reference to FIGS. 4(a)-(b), the exit aperture 516 controls the
spread of the light beam emitted from the end of the second light
guide 522. FIG. 6 shows the stylus 510 when the cylinder 552 is not
in contact with a surface. As such, the exit aperture 516 is
farther away from the end of the second light guide 522. When the
cylinder 552 is in contact with a surface (not shown), the exit
aperture 516 is closer to the end of the light second light guide
522, resulting in a broader beam spread.
In general, ambient light, including light emitted by a user input
device proximate the tip 518 of the stylus 510, is collected by the
entrance aperture 514. The first light guide 520, which is in
optical communication with the entrance aperture 514, directs the
light to reflector 560, where it is directed back through the first
light guide 520 and into the second light guide 522. Second light
guide 522 then directs the reflected light through the exit
aperture 516.
As described herein, the styli of the present disclosure produce
defined intensity profiles detectable by a user input device. Any
defined intensity profile that is suitable for detection may be
produced. For example, FIGS. 7(a)-(c) are schematic diagrams of
various embodiments of defined intensity profiles that may be
produced by a stylus of the present disclosure. In FIG. 7(a), a
defined intensity profile 600(a) includes a dark region 610(a) and
a light region 612(a). The dark region 610(a) surrounds light
region 612(a). Such an intensity profile 600(a) provides a contrast
between the dark region 610(a) and the light region 612(a) that is
detectable by the user input device. In other words, defined
intensity profile 600(a) can be distinguished by a user input
device over other background noise, e.g., shadows produced the
user's hand, ambient light patterns, etc.
The defined intensity profile 600(a) may be any suitable size and
shape such that it is detectable by the user input device. Defined
intensity profile 600(a) may be produced by a stylus when the
stylus is proximate an input surface (i.e., sufficiently close to
or in contact with the input surface). If the stylus tip is in
contact with the input surface, then the stylus may be
substantially normal to the input surface to produce intensity
profile 600(a). It may be preferred that the size of the intensity
profile 600(a) is large enough so that a sufficient number of light
sensors are exposed so that the profile 600(a) can be detected.
FIG. 7(b) illustrates another defined intensity profile 600(b) that
includes a dark region 610(b) that surrounds a light region 612(b).
Such a profile may be produced when a tip of the stylus (e.g., tip
18 of stylus 10 of FIG. 1) is in contact with an input surface of a
user input device at an angle to the input surface's normal vector.
As described herein, the tip may include a conformable member
(e.g., conformable member 130 of stylus 110 of FIG. 2(a)) that
partially conforms to the input surface. The conformal nature of
such a stylus can allow the stylus to emit an intensity profile
that is distinguishable by a user input device over other
background profiles.
Another defined intensity profile 600(c) is illustrated in FIG.
7(c). Defined intensity profile 600(c) includes a dark region
610(c) that partially surrounds a light region 612(c) such that a
user input device may distinguish defined intensity profile 600(c)
over other background profiles. Defined intensity profile 600(c)
may be produced by a stylus of the present disclosure when the
stylus is in contact with an input surface at a glancing angle to
the input surface. At such an angle, only a portion of the tip of
the stylus may be in contact with the input surface, thereby
producing dark region 610(c).
FIGS. 8(a)-(b) are schematic diagrams of an embodiment of one way
of using a passive light stylus 710 in a user input device 714.
Electronic display system 700 includes a stylus 710 and a user
input device 714. Stylus 710 may be any stylus described herein.
Stylus 710 is configured to collect light and emit the collected
light through a tip 712 of the stylus 710. The stylus 710 produces
a defined intensity profile detectable by the user input device 714
when at least a portion of the tip 712 of the stylus 710 is
proximate (i.e., within a sufficiently small distance of, for
example a distance predetermined by a threshold, or in contact
with) a surface.
System 700 also includes user input device 714, which includes a
layer 720 and light sensors 730. The layer 720 includes an input
surface 722. The light sensors 730 are configured to sense light
transmitted through the input surface 722. If input surface 722 is
a surface of layer 720, the light sensors 730 can be disposed on
opposing surface 724 of layer 720, or the light sensors 730 can be
provided in any other manner so that input surface 722 is
interposed between the stylus 710 and the light sensors 730. For
example, the light sensors 730 can be formed as part of an
electronic display, and layer 720 can be a layer of that display,
or a layer disposed over (whether in contact with or apart from)
that display.
By knowing which of the sensors 730 are sensing the emitted light,
the position of the defined intensity profile at the input surface,
or other reference plane, can be determined. The stylus 710 and
light sensors 730 can thus be used as a user input device by
associating various functions of an electronic system or display
with the positional information. An exemplary array of light
sensors is an array of photo diodes, such as those disclosed in the
following publications: WO 03/071345; U.S. Pat. No. 6,337,918; U.S.
Pat. No. 5,838,308; JP 10-187348; JP 10-283113; JP 58-086674; JP
60-198630; JP 60-200388; JP 61-006729; JP 61-075423; JP 11-282628;
and JP 2003-66417. Other suitable arrays of light sensors include
the light-emitting devices of organic electroluminescent displays
(OLEDs) as disclosed in International Publication WO 03/058588. In
addition to emitting light, OLED devices can also detect light. As
disclosed in WO 03/058588, by properly modulating the emitting and
detecting functions of OLED devices, display pixels can perform a
dual function seemingly simultaneously. As such, it may be possible
to fit existing OLED displays with new electronics to convert the
existing displays into dual function displays and input devices.
The pixel transistors already provided in active matrix liquid
crystal displays (AMLCDs) can also be used to detect light. Light
sensor arrays can be provided as a separate device coupled to the
user input system, as a separate layer in a user input system, or
as an integral part of a display device. When the light sensors 730
are integrated into a display device such as an LCD, it may be
desirable to locate such sensors 730 within areas covered by the
black matrix, for example, so that there is little or no reduction
in pixel area. In such a case, it may be desirable to form
apertures in the black matrix aligned with the light sensors 730 to
allow light to reach the light sensors 730. This can be done during
patterning of the black matrix.
The light sensors 730 are disposed to sense light transmitted
through the layer 720. Light sensors 730 are spaced a distance S
apart, center-to-center, and are set a distance P below the input
surface 722. The defined intensity profile produced by the stylus
710 includes a diameter at the plane of the sensors 730. To
increase the likelihood that the defined intensity profile will be
detected at all locations, the diameter of the defined intensity
profile is desirably on the order of detector spacing S. In this
case, the positional resolution of profile location determination
is equal to 1/S.
The user input device 714 also includes electronics 740 coupled to
the light sensors 730. The electronics 740 can include any suitable
electronics, e.g., controller(s), software, etc. The electronics
740 are configured to determine the location of the defined
intensity profile produced by the stylus 710 at a reference plane.
The reference plane can be positioned in any suitable location. It
may be preferred that the reference plane is the input surface 722
of layer 720.
User input device 714 can also include an optional electronic
display 750. When a display 750 is included, the input surface 722
can include an exterior surface of the electronic display 750. Any
suitable display may be included, e.g., liquid crystal display,
organic electroluminescent display. When a display 750 is included,
it may be preferred that the light sensors 730 are integrated into
a transistor array that controls pixels of the electronic display
750 as is described, e.g., in U.S. Pat. No. 6,028,581. The
electronic display 750 is disposed to display information through
the input surface 722 of the user input device 714.
In FIG. 8(a), the tip 712 of stylus 710 is a distance D from the
input surface 722. It may be preferred that the light sensors 730
are controlled such that the defined intensity profile produced by
the stylus 710 is detected only when at least a portion of the tip
712 of the stylus is proximate the input surface 722 of the input
device 714. As shown in FIG. 8(a), the tip 712 of the stylus 710 is
at distance D such that the tip 712 is not proximate the input
surface 722. Therefore, the user input device 714 does not detect
the defined intensity profile produced by the stylus 710.
In FIG. 8(b), the tip 712 of stylus 710 is proximate the input
surface 722. User input device 714 then detects the defined
intensity profile. The electronics 740 then determine the location
of the defined intensity profile produced by the stylus 710 at a
reference plane, e.g., the input surface 722. Any suitable image
processing technique may be used to determine the location of the
stylus 710, e.g., WO 03/071,345.
All references and publications cited herein are expressly
incorporated herein by reference in their entirety into this
disclosure. Illustrative embodiments of this disclosure are
discussed and reference has been made to possible variations within
the scope of this disclosure. These and other variations and
modifications in the disclosure will be apparent to those skilled
in the art without departing from the scope of this disclosure, and
it should be understood that this disclosure is not limited to the
illustrative embodiments set forth herein. Accordingly, the
invention is to be limited only by the claims provided below.
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